Two different synthetic pathways for the chromogenic N-pivot lariat crown ethers (1a and 1b) were studied comparatively. It was found that N-(2-picrylaminoethyl) monoaza-12-crown- 4 (1a) could be synthesized conveniently by the N- cycloalkylation of N-picrylethylenediamine (2) with 1,11- diiodo-3,6,9-trioxaundecane (3) but this method became invalid to obtain 15-crown-5 (1b) , however the picryl chloride reacted with N-(2-aminoethyl) monoazacrown ethers (5a and 5b), which were obtained via the cyclozation of N-tosylethylenediamine (6) or N-(2-tosylamindoethyl) diehanolamine (7) followed by detosylation giving 1a and 1b in good yield.

Key words: SYNTHESIS, CROWN ETHER